package bit_pratice.day3;

import java.util.Scanner;

/**
 * @author 美女
 * @date 2022/05/03 19:04
 **/
public class Num1_teacherTalk {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        String cur = "";
        String ret = "";
        int i = 0;
        for (; i < str.length(); i++) {
            //遍历字符串
            char ch = str.charAt(i);
            if (ch >= '0' && ch <= '9') {
                cur = cur + ch + "";
            } else {
                //此时不是数字串，判断cur与ret中哪个数字串长
                if (cur.length() > ret.length()) {
                    //cur中数字串长，把它给ret
                    ret = cur;
                } else {
                    //cur中数字串短，ret中不变，清空cur
                    cur = "";
                }
            }
        }
        if (i == str.length() && (cur.length() > ret.length())) {
            ret = cur;
        }
        System.out.println(ret);
    }
}
